Signments



Oct. .18, 1932. M, AwAblER Re. 18,628

VALVE FOR WIRELESS TELEGRAPHY OR TELEPHONY Original Filed July 13, 1925 gwuentoz ag/Q 111/74 VCQM attoamcq Reissued Oct. 18, 1932 UNITED STATES PATENT OFFICE JACQUES ANTOINE MARIE HAWADLIER, OF PARIS, FRANCE, .ASSIGNOR, BY MESNE AS- SIGNMENTS, TO OLD COLONY TRUST coMrA Y, A CORPORATION or. MAssAoHU- Original No. 1,666,010, dated April 10, 1928, Serial 110.43259, inea ui 13, 1925, and in France Augusta, 1924 Application for reissue filed October 15,1928. Serial No. 312,710.

My invention relates to a valve of the kind used in wireless telegra'phy or telephony, especially constructed with the object of utilizing alternating current from the town supply to heat the cathode.

With this object in view the single filament generally used in triode valves is substituted according to my invention by a tubular cathode the heating of which is ensured by the action of a central auxiliary filament branched upon the alternating current from the town supply. In order to avoid all contact of this auxiliary filament with the tubular sending cathode, the latter is mounted and supported upon a tubular part of refractory and insulating material. The cathode is moreover specially constructed with the object of ensuring a regular transmission.

special mode of supporting the auxiliary filament and the tube carrying the cathode.

The appended drawing shows by way of example two diflerent modes of construction of a valve made according to th'e present inlating and homogeneous material such for instance as quartz. The cathode a which is designed for the sending 01f of electrons is constituted by a tube made of a metal such as tungsten or molybdenum acting as carrier for-a layer of active substances capable of emitting at moderate temperatures or in the body of which the active substances are in corporated or mixed. The oxides or oxide mixtures studied by Wehnelt such for lIl-J stance as calcium, barium, strontium or.

thorium oxides,-etc., may be employed advantageously to constitute the active substances. The cathode is connected to the plate and grid circuits by the lead- 0.

The entire structure comprising parts a The invention has further for its object a,

VALVE FOR WIRELESS TELEGRAPHY 0R TELEPHONY which inv addition to that of the cathodewill bring the latter to a degree of heat suificient to produce an abundant emission Of free electrons.- The filament" 03 will be branched on an alternating current, such for instance as the circuit of the town supply, by means of leads e and 6 The insulating cathode support 6 is kept centered around the auxiliary filament d by means of tubular parts f and f of nickel for instance secured by pinching upon the leads e and 6 these tubular parts serving thus to retain both ends of the auxiliary filament cl in position. This arrangement has also for its object to enclose the cen'tralauxiliary filament in order to avoid a'prejudicial emission of electrons bythe latter.

- The valve is completed in the usual manner by a grid 9 and a plate It connected with their respective circuits by the leads 2' and In the mode of execution shown in Fig. 2" the cathode is placed horizontally. The auxiliary heating filament d secured to the leads e, e is wound helically for part of its length only and in the middle in order to allow of heating the middle part of the quart-z tube without putting the admissions of current in the interior of said tube. The latteris carried by means of supporting sleeves 70 k which are fixed by soldering to the current admissionsand contribute to the cooling of the extremities of the quartz tube. The sleeves 7c are made of a refractory metal such for instance as molybdenum.

The cathode being formed by a rigid undeformable part it will be possible to bring the grid and plate nearer together without any risk of producing a short circuit caused by electrostatic attraction. I

In the course of manufacture the occluded gases are completely evacuated from the difierent'parts ofthe valve and neces sary care should be taken during the p'ump-' cathode, conductors for supplying alternat-' in" current supporting the filament, a quartz between the filament and cathode, sup-V porting the latter and projecting beyond the tube ends thereof, and collars at both ends of the quartz tube supporting the same and the said conductors.

2; A valve for wireless telegraphy and te+ lephony comprising a grid, a' plate, a tubular cathode coated with electron emitting oxides, an electrically non-conducting and heat transmitting tube longer than said cathode supporting the latter and projecting be yond its ends, a spiral heating filament in said tube solely in the middle part thereof, alternating current supply conductors for said filament and supporting the same, nickel collars supporting'the ends of said tube and electrically connected to said conductors and supported thereby.

3. A cathode structure comprising a hollow member adapted to emit electrons upon suitable thermal energization, a heating filament within and spaced from said electron. emitting member and means comprising at least one tapered member engaging one end of said electron emitting member for maintaining said heating member in desired relationsh1p to said electron emitting member.

4. 'A cathode structure comprising a hollow insulating member having an equi-potential cathode surface, aheater, conducting members adapted to supply heating current to said heater, and a metal collar on at least one conducting member engaging said insulating member, whereby the said cathode surface and heater member are maintained in desired relation.

5. In a vacuum tube, an anode, a grid surrounded by said anode, a cathode structure surrounded by said grid and anode, said cathode structure comprising an equi-potential surface, a heater therefor, separated from said surface by a free space, conducting members for said heater and equi-potential surface, said conducting members comprising the-sole means of support for said cathode structure, and means comprising metal collars fixedly secured on said conducting members for so supporting said equi-potential-surface with respect to said conducting members and heater that an insulating surface is interposed between each collar and said equi-potential surface.

6. Acathode structure comprising a heating member, conducting members therefor,

l collars fixedly secured to said conducting tained in desired relationship to each other.

7 In a thermionic tube having a hermetically sealed evacuated envelope, a cathode and cooperatingelectrodes entirely enclosed in said envelope, said cathode comprising a single hollowmember adapted to emit elec'- trons upon thermal energization s thereof, members closing the ends of said hollow member and extendingv outwardly therebeyond, said closing members having reduced por tions adapted to fit the ends of said hollow member, a; conducting member extending through each of said closing members, and a heating filament inside said hollow member supported and energized byv said conducting members. i

8. In a thermionic tube having a hermetically sealed evacuated envelope, a cathode and cooperating electrodes entirely enclosed in said envelope, said cathode comprising a single hollow member adapted to emit elec trons upon heating, plugs closing the ends ofsaid hollow member and extending outward- 1y therebeyond, a conducting member extending through each of saidplugs, a heating fila ment Within said hollow member energized through said conducting members, and means for retainingsaid plugs in predetermined position on said conducting members.

9. In a thermionic tube having a hermetically sealed evacuated envelope, a cathode and cooperating electrodes entirely enclosed in said envelope, saidcathode comprising a hollow elongated member having an external surface adapted to emit electrons upon heating, plugs closing the ends thereof and extending outwardly therebeyond, conducting members extending through the said plugs to the interior of the said hollow member, a heating filament in said hollow member for heating the same, lead-in members extending into said hollow member for supplying current to said filament, said plugs engaging said lead-in members and supporting said filament spaced from thefinner walls of said hollow member.

'10. A cathode structure comprising an equi-potential cathode surface, a hollow insulating 'member supporting said cathode surface, a heater, conducting members adapted to supply heating current to said heater. and a metal supporting member on at least one conducting member engaging said insulating member, whereby the said cathode sur face and heater member are maintained in desired relation. v

11. In a thermionic tube having a hermetically sealed evacuated envelope, a cathode and cooperating electrodes entirely enclosed in said envelope, said cathode comprising a single hollow member adapted to emit electrons upon suitable thermal energization, a heating member Within saidelectron-emitting member, and a pair of plugs engaging the opposite ends of said hollow member, said heating member being supported between said plugs and held thereby spaced from said electron-emitting member.

In testimony whereof, I have hereunto subscribed my name this 29th day of September, 1928. t

JACQUES ANTOINE MARIE HAWADIER. 

